Right Prism: a prism in which all of the lateral faces are rectangles.
Dihedral Angle: the figure formed by two half-planes with a common edge. Each half-plane is called a face of the angle, and the common edge of the half-planes.
Oblique Prism: has at least one nonrectangular lateral faces

Prism: a polyhedron that consists of a polygonal region and its translated image on a parallel plane, with quadrilateral faces connecting corresponding edges.
external image triangular_prism_rightangel.jpg
Base of a Prism: The faces formed by the polygonal region and its image.

Lateral Faces: The faces of a prism or pyramid that are not bases.

Lateral Edges of a Prism: The edges of the lateral faces of a polyhedron that are not edges of either base.

To find a diagonal of a right rectangular prism: L^2 + W^2 + H^2 = D^2
- that is only with diminsions l x w x h

Rhombus: parallelogram with four congruent sides.
Diagonal of a right rectangular prism
in a right rectanglar prism with dimensions lxwxh, the length of a diagonal is given by d= the square root of l2+w2+h2.